1. Field of the Invention
The invention relates to a hybrid vehicle including an engine that is able to output driving power, a motor that is able to output driving power, a battery that is able to exchange electric power with the motor, and a navigation system that sets a travel route to a destination and carries out route guidance.
2. Description of Related Art
There has been suggested a hybrid vehicle, for example, described in Japanese Patent Application Publication No. 2010-280250 (JP 2010-280250 A). The hybrid vehicle includes an engine and a motor generator as power generating sources, a battery that exchanges electric power with the motor generator, and a navigation unit that displays a road map around a current location or searches for a route from a departure place to a destination. When the state of charge (SOC) of the battery is higher than a usage lower limit value and a required driving power value is smaller than or equal to a power threshold, an EV traveling mode is selected. In the EV traveling mode, the engine is stopped, and the vehicle is caused to travel with the use of the motor generator as a power generating source. On the other hand, when the state of charge of the battery is lower than or equal to the usage lower limit value or when the required driving power value is larger than the power threshold, an HV traveling mode is selected. In the HV traveling mode, the engine is used as the power generating source. In the hybrid vehicle, the amount of electric power usable in EV traveling (the amount of usable electric power) and an estimated value of the amount of electric power (estimated required amount of electric power) required at the time when the vehicle travels in the EV traveling mode to a destination are successively compared with each other. The power threshold is set to a low threshold when the estimated required amount of electric power is larger than the usable amount of electric power, and the power threshold is set to a high threshold when the usable amount of electric power is larger than the estimated required amount of electric power. Thus, it is possible to improve practical fuel economy.